Lock

ABSTRACT

A resettable lock of the cylinder type constructed of coaxial cylinders, one inside the other. The rotatable cylinder slidably mounting a plurality of tumblers. The inner wall of the outer cylinder having a radial opening functioning as the open terminal for the tumblers when a key inserted into the lock contacts the various pusher elements and positions all the associated tumblers at the terminal simultaneously. The lock is rendered pick resistant by an element overlying the tumblers.

United States Patent 1191 mvguqw TIIII/I/{E Pearson June 18, 1974 [54] LOCK 2.424.514 7/1947 Sterner 70/383 [76] Inventor: Rune S. Pearson, 22625 Ellinwood I Dr Torrance, C lif 90505 Primary Emminer-Robert L. Wolfe H d ec 6 1972 Attorney, Agent, or Firm-Christ1e, Parker & Hale [21] Appl. No.: 318,663 [57] ABSTRACT A resettable lock of the cylinder type constructed of [52] US. Cl 70/363, 70/383, 770623119, Coaxial Cylinders one inside the other The rotatable cylinder slidably mounting a plurality of tumblers. The 19/18, /ii il f gg g a inner wall of the outer cylinder having a radial open- 76/41 41 ing functioning as the open terminal for the tumblers when a key inserted into the lock contacts the various [56] R f Cit d pusher elements and positions'all the associated tume erencfrs e blers at the terminal simultaneously. The lock is ren- UNITED STAT ES PATENTS dered pick resistant by an element overlying the tum- 2021.443 1 1/1935 Deutsch 7. 70/384 X blers. 2.024.030 12/1935 Deutsch... 2,044,534 6/1936 Lejbowicz 70/383 11 Claims, 18 Drawing Figures LOCK DISCLOSURE OF THE INVENTION This invention relates to a lock and more particularly to a resettable lock means adaptable to a cylinder, sliding or combination type lock. The resetting is accomplished without having access to the back of the lock or requiring the lock to be disassembled. Various types of resettable locks, including cylinder locks, have been developed throughout the years. Some typical prior art cylinder type locks are disclosed in US. Pat. Nos. 2,044,534; 2,424,514; 1.036,764 and 1,819,853. All of these prior developments have the disadvantage that 'they are either too large and complex, employ too many components, are too easy to pick or have a limited movement of the rotatable cylinder and/or offer access to the internal parts of the lock. The more recently developed resettable locks differ greatly in principle from this development and usuallyonly provide for a limited number of resettings, approximately 8 to 10 settings. The resettable lock described hereafter is fully resettable to every possible tumbler setting. Thus, a resettable lock of this type having six tumblers, each tumbler having 10 possible settings would be fully resettable to any of its 1,000,000 possible settings. In addition to the resetability feature, this lock can also be made highly pick resistant through the addition of a pick resist member.

The security provided by any lock is dependent upon three factors:

1. The strength of the material used to construct the locks. This determines the ability of the lock to resist being opened through the application of physical force.

2. The pick resistancy provided in the internal functioning of the lock. Most attempts at making locks highly pick resistant have concentrated on adding additional rows of tumblers or using different types of tumblers within the samelock. This naturally results in a more complex lock and hence a more costly lock.

3. The length of time a lock has been in use. Even a lock constructed of high strength materials and having highly pick resistant internal design will still be vulnerable to being opened by keys in the possession of unauthorized persons due to keys being lost, stolen, copied, kept by terminated employees or former tenants, etc.

Also, the existing lock and key system has various shortcomings as can be readily understood from the following. The lock manufacturer must offer his customers a wide selection of differently set locks so that one lock will not be accidentally or .purposely opened by someone else having the same make key. Ideally,

, ing those of locks in products previously sold to the same customer. As a result, the original equipment manufacturer must keep a fairly large inventory of differently set locks, keep records of various customers settings, match specifically set locks to standard products, thereby resulting in increased costs for the original lock manufacturer. The class of lock users can be divided into two general groups. The first group would be those who have many locks with different people using locks at different times, or at the same time. This would be the case for hotels, motels, apartments, offices, plants, vending machines, etc. The more locks a user has, the greater the problems of key control and the maintenance of security. Some of the factors which reduce the security offered by any such lock are keys which are lost or stolen, unauthorized key duplicates being made and employee turnover. The only way to overcome these disadvantages is to maintain a regular program of lock rotation or resetting. This is very time consuming and costly. The second group would be the average person who may normally carry from five to seven different keys for his home, auto, office, etc. The most common problems this group encounters are losing keys, locking oneself out, leaving keys at home or office and dislike of having to carry around a bundle of keys. If such a person loses his key, has his keys stolen, or locks himself out, it is time consuming and costly to have a locksmith make a new key, reset the lock or pick the lock.

Despite the long time span during which locks have been under development, there is still a need for a lock that can overcome most of the above described short comings of existing locks and keys; that is, a lock of simple construction which is highly pick resistant and which can be easily reset.

The present invention provides an improved resettable cylinder type of lock which is adaptable to a sliding action lock or a combination type lock that is constructed in a simple fashion of a few components and adaptable to assembly operations that are identical for all locks even though they may have different settings. The lock of the present invention is constructed of a rotatable and a nonrotatable cylinder that allows the rotatable cylinder to be rotated 360' in both directions. For a lock provided with six tumblers, approximately one million settings are provided. The lock of the present invention may be made highly pick resistant and does not afford an opening into the inner portion of the lock to allow the lock to be improperly opened to obtain access to the secured area. The lock is employed with keys that allow the lock to be readily reset for any combination in a minimum amount of time but only when the lock has been opened. The setting and resetting may be accomplished in less than 20 seconds employing a preferred type of key for the lock.

From a structural standpoint, the present invention comprehends a lock comprising two cylinders arranged coaxially, one inside the other, with one of the cylinders being fixed while the other cylinder is rotatably mounted. The rotatable cylinder has a plurality of longitudinally extending slots spaced around the outer periphery thereof for slidably receiving a tumbler. A tumbler may be provided for each of the cylinder slots and is slidably mounted in the slot. The nonrotatable cylinder is constructed with a tumbler receiving slot arranged at a preselected location within the internal wall thereof and extending radially thereof. A pusher element is slidably mounted with the nonrotatable cylinder and adjacent the tumblers of the rotatable cylinder.

The pushers control the position of the tumblers and thereby the setting required for unlocking the lock. Means for continuously urging the pushers in a preselected direction or in the direction of the outer face of the lock is provided. The outer periphery of the tumblers and the pushers are constructed and defined in a releasable interlocked relationship to cause a tumbler to move in the direction of the movement of the pusher and to prevent the rotation of the rotatable cylinder except when all the tumblers are in alignment with the common tumbler receiving slot. The tumbler may be constructed in a U-shaped configuration with the tumbler receiving slot having a complementary shape to receive a tumbler when moved thereto as a terminal location. The lock may further include means for rendering the lock pick resistant which may be secured to the nonrotatable cylinder in a permanent relationship.

These and other features of the present invention may be more fully appreciated when considered in the light of the following specification and drawings, in which:

FIG. 1 is a front elevational view, showing portions in dotted outline, of the lock embodying the present invention with the tumblers in that position which would allow the inner cylinder to rotate; i.e., the lock can be opened.

FIG. 2 is a cross sectional view of the lock illustrated in FIG. 1 taken along the line 2-2 and illustrating the lock in an open position and with a bolt illustrated in dotted outline coupled to the rotatable element thereof;

FIG. 3 is a detached, front elevational view of the outer cylinder of the lock illustrated in FIGS. 1 and 2;

FIG. 4 is a cross sectional view of the outer cylinder illustrated in FIG. 3 and taken along the line 4-4;

FIG. 5 is a detached, front elevational view of the inner cylinder of the lock illustrated in FIGS. 1 and 2;

FIG. 6 is a cross sectional view of the inner cylinder illustrated in FIG. 5 and taken along the line 6-6;

FIG. 7 is an end elevational view of the cylinder of FIG. 6 taken along the line 7-7;

FIG. 8 is a detached, cross sectional view of a tumbler for use in the lock of FIGS. 1 and 2;

FIG. 9 is a detached, longitudinal view of a pusher el ement for use in the lock of FIGS. 1 and 2;

FIG. 10 is a front elevational view, with portions broken away, of the lock of the type illustrated in FIGS. 1

and 2 illustrating the tumbler in a locked condition and having a pick resistant element arranged therein and with the pusher element removed;

FIG. 11 is a partial elevational and cross sectional view of the lock of FIG. 10 taken along the line 11-11;

FIG. 12 is a detached, longitudinal view of the pick resistant element as illustrated in FIGS. 10 and 11.

FIG. 13 is a right-end elevational view of the pick resistant element as illustrated in FIG. 12;

FIG. 14 is a sectional viewof a key usable with a lock of the type of FIGS. 1,2,10 and 11 and taken along the line 14-14 of FIG. 15;

FIG. 15 is an end elevational view of the key of FIG. 14;

FIG. 16 is a sectional view of a modified quick change key for use with a lock of the type illustrated in FIGS. 1, 2, l0 and 11 and taken along the line 16-16 of FIG. 18;

FIG. 17 is an end elevational view of the key of FIG.

16 illustrating the key in a resetting condition; and

FIG. 18 is an end elevational view of the key of FIG. 16 illustrating the key in a neutral condition.

Now referring to the drawings, the detailed construetion of the lock 10 of the present invention will be examined. The lock 10 of the present invention is illustrated in the drawings in the form of a cylinder type lock although it should be understood that the concept of the present invention is adaptable to a sliding action type lock or a combination type lock. The lock 10 generally comprises an outer cylinder 11 having a rotatable cylinder 12 arranged coaxially therewith. The outer and inner cylinders 11 and 12 are arranged between a back plate 13 and a front or face plate 14. The rotatable cylinder 12 mounts a plurality of tumblers 15 that are slidable along a plurality of grooves 126 spaced around the outer periphery of the rotatable cylinder 12. The lock 10 further includes a plurality of pusher elements 16 mounted with the face plate 14 and releasably interengaged with an individual tumbler 15. The pusher elements 16 have an axial aperture 16 for mounting a compression spring 17 therein with its opposite end seated to the back plate 13.

The detailed construction of the inner cylinder or the rotatable cylinder 12 can be best appreciated by examining FIGS. 5-7 wherein the detached views of the cylinder are illustrated. An important aspect of the inner cylinder 12 is the provision of a plurality of slots or guideways 12G arranged around the outer periphery of the inner cylinder 12. The guideways 12G may be spaced around the outer periphery at approximately 60 increments, as best appreciated from examining FIG. 5. The guideways 126 are defined inwardly of the outer end of the cylinder 12 or the right hand end as illustrated in FIG. 6. The depth of the guideways 126 are defined to be less than the depth of a tumbler 15 that is adapted to be slidably mounted therein. In one practical embodiment of the invention, the depth of the guideways is constructed to be approximately onehalf of that of a tumbler 15. The outer end, or righthand end, of the inner cylinder 12 is also provided with a key slot 12K to receive a key inserted through the face plate 14 as will become more evident hereinafter. The opposite end of the rotatable cylinder 12 or the left-hand end as illustrated in FIG. 6 may have a threaded aperture 12L extending a preselected distance therein for securing hardware associated with the lock 10, as illustrated in FIG. 2.

The details of the outer cylinder or the fixed cylinder 11 are illustrated in FIGS. 3 and 4 and should be examined at this time to facilitate the understanding of the relationship and coaction between the inner cylinder 12 and the outer cylinder 11. The outer cylinder 11 has a plurality of spaced apart apertures arranged inwardly of the outer periphery for accommodating the pusher elements 16 and the tumblers 15 therein; see FIGS. 1

and 2. In this instance, six apertures 111 are arranged Y approximately 60 degrees apart and extend longitudinally of the cylinder as is evident from examining FIGS. l3. An important feature of the construction of the outer cylinder 11 is the provision of the tumbler receiving slot means illustrated in FIG. 4 as two spaced apart tumbler receiving slots llTR arranged intermediate the ends of the cylinder 11. The tumbler receiving slots llTR are spaced apart a preselected distance in accordance with the selected configuration for the tumblers 15. As illustrated in FIG. 4, the tumbler receiving slots llTR are spaced apart to receive and accommodate a U-shaped tumbler 15. The tumbler receiving slots llTR function as a terminal point for the movement of the tumblers relative thereto so as to allow the lock to be opened when all of the tumblers are simultaneously pushed to be received in the slots llTR. The slots llTR afford the necessary clearance to allow the tumblers to rotate within the outer cylinder 11 which is not possible at any other position of the tumblers 15. t

The tumblers 15, as illustrated in FIGS. 2 and 8, are of a U-shaped configuration having two upstanding arms extending a preselected distance above the base portion thereof so that they are in alignment with the tumbler receiving slots llTR. The outer ends of the upstanding arms of the tumbler 15 are provided with a plurality of V-shaped grooves having an angle on the order of 60 for releasable interlocking with the adjacent surface of a pusher element 16 as indicated in FIG. 8.

The pusher elements 16, as illustrated in FIGS. 2 and 9, are arranged with a plurality of V-shaped slots corresponding with the V-shaped slots for the tumblers 15 for releasable interengagement therewith. To this end, the slots for the pusher elements 16 may be on the order of 60 as indicated in FIG. 9. The left-hand end of the pusher elements 16, as illustrated in FIG. 9, is provided with an axial aperture 16A for receiving and accommodating the compression spring 17 therein, as

. illustrated in FIG. 2. When the pusher elements 16 are mounted in the lock 10, the right-hand end is adjacent the outer face of the face plate 14 and even when moved inward to their extreme, the pusher elements will still partially remain within the face plate 14 to prevent access to the internal structure of the lock. The back plate 13 is defined with a plurality of protruding fingers 13 extending inwardly of the apertures 16A for the pusher elements 16 to function as a seat for the opposite ends of the springs 17, or the left-hand end as illustrated in FIG. 2. The compression springs 17, then, continuously urge the pusher elements 16 in the direction of the outer face of the face plate 14. The interengagement of a tumbler 15 and a pusher 16 cause the tumblers to move in unison with the movements of the pushers 16. It will be recognized that the location of the tumblers may be set by varying the interengagement position of the tumblers l5 and pusher 16. FIG. 2 shows 10 possible settings. It will be recognized, then, that the lock 10 will be closed and the rotatable cylinder 12 will be retained in a nonrotatable relationship except when all of the tumblers 15 are arranged in alignment with the tumbler receiving slots 1 lTR. In any other position of the tumbler 15, the tumbler crosses the shear line between the fixed cylinder 11 and the inner cylinder 12 making it impossible to rotate the inner cylinder 12 in either direction.

A key that may be employed for unlocking the lock 10 and for adjusting the positions of the tumblers 15 and the pushers 16 is illustrated in FIGS. 14 and 15. This general type of key is shown in the art and comprises a plurality of adjustable probes 23 for engaging the outer end of the pushers 16. The probes 23 are illustrated as threaded to allow them to be adjusted to different lengths. In the embodiment of the key illustrated in FIGS. 14 and 15, the key 20 comprises a key head 21 having a key stem 22 secured thereto by means of a retaining ring (not shown) mounted in the groove 21R. The key head 21 mounts the plurality of adjustable probes 23. The probes 23 are adjustable so as to position a pusher 16 at preselected locations with respect to the tumbler receiving slots llTR. In this fashion, the starting points of each of the tumblers 15 employed in the lock 10 can be adjusted by varying the longitudinal extension to which the probes 23 extend outwardly from the key stem 22, while the tumblers 15 are out of engagement with pushers 16. In the embodiment illustrated for the key in FIGS. 14 and 15, the key head 21 may be made removable so that the probes 23 can be adjusted or reset while the key is still in the lock 10 and thereby resetting the lock at the same time. If the key head 21 is fixed to the key stem 22, then, the key can be reset only when it is outside of the lock and therefore cannot be used to reset the look. This is to prevent unauthorized lock resetting.

Assume, then, that a key 20 has been inserted into the lock 10 and the pushers 16 and the corresponding tumblers 15 have been moved by the probes 23 to position all of the individual tumblers 15 in alignment with the tumbler receiving slots 1 ITR, since only in this condition can the cylinder 12 be rotated. Under these conditions, if the cylinder 12 were turned 30 degrees into a clockwise direction, all of the tumblers 15 mounted on the rotatable cylinder 12 will be rotated 30 degrees therewith so as to be disengagedi from the individual pushers 16, as illustrated in FIG. 1. Examining FIG. 1, it will be noted that when the tumblers 15 are arranged in this fashion, they are occupying the spaced identified as space 2 in FIG. 1. At this time the lock 10 may be reset by moving each pusher l6 inwardly or outwardly in accordance with the desired setting for defining a new unlocking combination. It should be noted that during this time that because of the radial alignment of the tumblers 15 with the slots llTR that the tumblers 15 cannot be moved out of alignment therewith because the slots llTR restrain the tumblers 15 from any forward or backward movement as a result of their complementary construction. It should also be noted that if the inner cylinder 12 is rotated beyond the space 2 position to the next space between pushers 16, the tumbler 15 that occupied space 2 will be rotated so as to be received at the point identified as space 3" in FIG. 1. In the same fashion, the continuous rotation of the cylinder 12 allows the tumblers l5 1 to be sequentially placed between the successive positions of the pushers 16 throughout the 360 rotation of the inner cylinder 12 in both a clockwise and a counterclockwise direction to place the tumblers 15 back into interengagement with the individual pushers 16 at the new position for locking the lock when the key is removed. The key can be removed at positions spaced 60 apart for the structure illustrated. As shown in FIG. 1, the key can be removed at the 60, 180, 240 300 and 360 positions. It should be noted that if the key were removed at the points identified in FIG. I as the 30, 90, 210, 270 or 330 positions, the tumblers 15 would be out of contact with the pushers 16 and all of the pushers would return to their forward position or the right-hand position as illustrated in FIG. 2. At this time, the lock user could reset the key outside the lock 10 to any new setting, insert said reset key and simply turn the cylinder 12 the requisite 30 to have the lock 10 set to the new setting. It should also be noted that in order to prevent the accidental removal of the key at the reset positions, the face plate 114 has an insertion space denoted as X in FIG. l to match the lip extension on the key stem 22 for the key 20 to assure correct insertion of the key. It will, of course, be recognized that the face plate 14 may have a plurality of positions X spaced at 60 intervals to allow for removal of the key Ztl at various positions without accidentally resetting the lock It). It should also be noted that at this reset position, the lock can be reset while a key is in the lock if the key is constructed so as to be adjustable when in the lock.

Now referring to FIGS. MI and III, the lock 10 illustrated in FIGS. 1 and 2 is shown as it is modified to render it pick resistant. The lock 10 illustrated in FIGS. l and 111 is identical to the lock It) described hereinabove except that the pusher elements 16 are not illustrated in position to clarify the understanding of the pick resistant feature. Also, it should also be noted that the tumblers I are arranged outside or outwardly of the tumbler receiving slots HTR to render the inner cylinder 12 nonrotatable, or in a locked condition.

To appreciate the necessity for rendering the lock pick resistant, it should be understood that it has been found that a lock can be picked by exerting slight pressure on the inner cylinder towards the open position and at the same time depressing the pusher slowly until a slight movement can be felt as the tumbler reaches its open position. While this means of picking a lock is largely dependent upon the tolerances provided for the locking elements comprising the lock, it neverthelesss is an undesirable feature and should be eliminated on locks requiring maximum security. This is accomplished by the teachings of the present invention through the provision of the pick resistant element 30.

The pick resistant element 30, as incorporated in the lock assembly It) illustrated in FIGS. M) and ill occupies the position identified as the space 2 in FIGS. It and W and is permanently attached to the outer cylinder II, as best illustrated in FIG. lit). The pick resistant element 367 is of the same length as the tumbler guide ways 126 provided for the inner cylinder H2 and has the requisite V-shaped grooves for matching those of the tumbler 15. The pick resistant element is shown in detail in FIGS. 112 and 3. The pick resistant element 30 is provided with a plurality of V-shaped grooves extending along one outer edge thereof as is evident from examining FIGS. Ill and 12. The pick resistant element 30 is provided with a stopping edge 30E arranged on opposite sides of the tumbler receiving openings 3TRz see FIGS. 12 and 113. The tumbler receiving openings EMDTR are spaced apart to coincide with the tumbler receiving slots llllTR provided for the outer cylinder 11 when they are in an open position. Accordingly, whatever setting has been selected for the lock the grooves of the tumblers I5 will enter into the matching grooves of the pick resistant element 30 and move clockwise until a space denoted as space Z in FIG. 10 is fully occupied. If the tumbler I5 is not in a correct open" position, it will be arrested by the stopping edge SIDE. To this end, the tumbler receiving slots for the pick resistant 30 are identified as the slots 30TR and are arranged intermediate the stopping edge 30E. Similarly, when the tumblers 15 are in their open position or in alignment with the slots illiTR, the tops or ends of the arms of the U-shaped tumblers 15 will pass through their respective slots LWTR of the pick resistant element 349 to allow the cylinder T2 to be rotated. In this fashion, then, the incorporation of the pick resistant element 30 into the lock It) makes it impossible to feel the open position once the grooves of the tumblers 15 are interlocked with the matching grooves of pick resistant element 39 since no backward or forward movement of the tumblers 15 can occur. It will also be noted that the pick resistant element 30 can be moditied by providing the stopping edge 30E in the center of the element 30 instead of being located on one side of the pick resistant element 36 so as to make the lock pick resistant in both clockwise and counterclockwise directions. It should now be recognized that with the positioning of the element 16 in the lock It) having the pick resistant element 30 that the operation of the lock as to the movement of the tumblers 15 is identical as described hereinabove for the locks of FIGS. 1 and 2.

Now referring to FIGS. ltd-Its, the structure for a quick change key 4t]! will be examined. The key 4th comprises a stem 41 mounting a plurality of tumbler setting knobs 12, six are illustrated, spaced around the outer periphery of the stem 41. A key head 43 is rotatably mounted to the key stem 41. To set a lock 10 with such a key, the key 44 set to the correct opening combination is inserted into the lock 10 or In with the key head 43 in the neutral position as illustrated in FIG. 18. With the key 40 in this position, the key head 43 is turned 30 to the right to the reset position, as illustrated in FIG. H7. The tumbler setting knobs 42 are numbered so that they can be identified relative to the desired setting; see FIG. 17. The knobs 42 are now turned to their new setting, the key head 43 is returned to the neutral position or starting position and the key 40 removed from the lock it or It).

What is claimed is:

1. A lock comprising two cylinders arranged coaxially, one inside the other, one of. the cylinders being adapted to be nonrotatable with the other cylinder being rotatably mounted, the rotatable cylinder having a pluraltiy of longitudinally extending slots spaced around the outer periphery thereof for slidably receiving a tumbler, at least a single tumbler slidably mounted in one of said slots,

the nonrotatable cylinder having a tumbler receiving slot constructed and defined at a preselected location within the internal wall thereof and extending radially thereof for accommodating the tumbler, and

a pusher slidably mounted within the nonrotatable cylinder adjacent the tumbler, means for continuously urging the pusher in a preselected direction,

the outer peripheries of the tumbler and pusher being constructed and defined in a releasable interlocked relationship to cause the tumbler to move in the direction the pusher is moved and to prevent the rotation of the rotatable cylinder except when the tumbler is in alignment with said tumbler receiving slot. 2. A lock comprising a pair of coaxially arranged cylinders, one of the cylinders being arranged to be rotatable relative to the other cylinder, the rotatable cylinder slidably mounting a plurality of tumblers adapted to be moved longitudinally thereof,

a plurality of tumblers mounted in sliding engagement with the rotatable cylinder, and

a corresponding plurality of pusher elements each mounted adjacent a tumbler and arranged in engagement therewith to cause the tumbler to move in unison with the movement of the pusher when the two are engaged,

the pair of cylinders being constructed and defined with an unlocking terminal section for each of the tumblers to cause each tumbler moved to the terminal section by a pusher to become disengaged from its pusher whereby upon movement of all of the tumblers to said terminal section the rotatable cylinder may be rotated.

3. A lock as defined in claim 2, including key means engageable with each of said pushers for setting same to preselected locking positions.

4. A lock as defined in claim 2 including means for rendering the lock pick resistant.

5. A lock as defined in claim 2 wherein the rotatable cylinder is rotatable through 360 in both directions.

6. A lock comprising a cylinder mounted in a nonrotatable relationship,

a rotatable cylinder coaxially mounted within the nonrotatable cylinder and having a plurality of spaced apart longitudinally extending slots arranged around the outer periphery thereof,

a corresponding pluraltiy of tumblers mounted in sliding engagement with an individual slot in the rotatable cylinder,

the internal wall of the nonrotatable cylinder having a radial opening to accommodate the tumblers to allow the rotatable cylinder to be rotated only when the tumblers are in alignment with the radial opening,

a plurality of movable means mounted between the cylinders and engageable and disengageable with the tumblers for slidably positioning the tumblers along the inner cylinder to preselected locations when in engagement with a tumbler to thereby maintain the lock in a closed condition; and for positioning the tumblers in alignment with the radial opening to open the lock and allow the rotatable cylinder to be rotated thereby disengaging the tumblers,

said plurality of movable means being accessible from one end of the rotatable cylinder to accommodate a key operative to engage the movable means for opening and closing the lock.

7. A lock as defined in claim 6 wherein the tumblers are U-shaped and said radial opening comprises a pair of spaced apart openings constructed and defined to accommodate the arms of a tumbler.

8. A lock as defined in claim 6 wherein said plurality of movable means each comprise pusher means having a central aperture extending from one end, a corresponding plurality of springs mounted in the apertures for urging all of the pusher means towards the key end of the cylinders.

9. A lock as defined in claim 6 including means for rendering the lock pick resistant.

10. A lock as defined in claim 9 wherein said pick resist means is secured to the nonrotatable cylinder.

11. A lock as defined in claim 9 wherein said pick resist means comprises an element interengaging the tumblers over their entire travel except when in the said open position. 

1. A lock comprising two cylinders arranged coaxially, one inside the other, one of the cylinders being adapted to be nonrotatable with the other cylinder being rotatably mounted, the rotatable cylinder having a pluraltiy of longitudinally extending slots spaced around the outer periphery thereof for slidably receiving a tumbler, at least a single tumbler slidably mounted in one of said slots, the nonrotatable cylinder having a tumbler receiving slot constructed and defined at a preselected location within the internal wall thereof and extending radially thereof for accommodating the tumbler, and a pusher slidably mounted within the nonrotatable cylinder adjacent the tumbler, means for continuously urging the pusher in a preselected direction, the outer peripheries of the tumbler and pusher being constructed and defined in a releasable interlocked relationship to cause the tumbler to move in the direction the pusher is moved and to prevent the rotation of the rotatable cylinder except when the tumbler is in alignment with said tumbler receiving slot.
 2. A lock comprising a pair of coaxially arranged cylinders, one of the cylinders being arranged to be rotatable relative to the other cylinder, the rotatable cylinder slidably mounting a plurality of tumblers adapted to be moved longitudinally thereof, a plurality of tumblers mounted in sliding engagement with the rotatable cylinder, and a corresponding plurality of pusher elements each mounted adjacent a tumbler and arranged in engagement therewith to cause the tumbler to move in unison with the movement of the pusher when the two are engaged, the pair of cylinders being constructed and defined with an unlocking terminal section for each of the tumblers to cause each tumbler moved to the terminal section by a pusher to become disengaged from its pusher whereby upon movement of all of the tumblers to said terminal section the rotatable cylinder may be rotated.
 3. A lock as defined in claim 2, including key means engageable with each of said pushers for setting same to preselected locking positions.
 4. A lock as defined in claim 2 including means for rendering the lock pick resistant.
 5. A lock as defined in claim 2 wherein the rotatable cylinder is rotatable through 360* in both directions.
 6. A lock comprising a cylinder mounted in a nonrotatable relationship, a rotatable cylinder coaxially mounted within the nonrotatable cylinder and having a plurality of spaced apart longitudinally extending slots arranged around the outer periphery thereof, a corresponding pluraltiy of tumblers mounted in sliding engagement with an individual slot in the rotatable cylinder, the internal wall of the nonrotatable cylinder having a radial opening to accommodate the tumblers to allow the rotatable cylinder to be rotated only when the tumblers are in alignment with the radial opening, a plurality of movable means mounted between the cylinders and engageable and disengageable with the tumblers for slidably positioning the tumblers along the inner cylinder to preselected locations when in engagement with a tumbler to thereby maintain the lock in a closed condition; and for positioning the tumblers in alignment with the radial opening to open the lock and allow the rotatable cylinder to be rotated thereby disengaging the tumblers, said plurality of movable means being accessible from one end of the rotatable cylinder to accommodate a key operative to engage the movable means for opening and closing the lock.
 7. A lock as defined in claim 6 wherein the tumblers are U-shaped and said radial opening comprises a pair of spaced apart openings constructed and defined to accommodate the arms of a tumbler.
 8. A lock as defined in claim 6 wherein said plurality of movable means each comprise pusher means having a central aperture extending from one end, a corresponding plurality of springs mounted in the apertures for urging all of the pusher means towards the key end of the cylinders.
 9. A lock as defined in claim 6 including means for rendering the lock pick resistant.
 10. A lock as defined in claim 9 wherein said pick resist means is secured to the nonrotatable cylinder.
 11. A lock as defined in claim 9 wherein said pick resist means comprises an element interengaging the tumblers over their entire travel except when in the said open position. 